The reproductive biology of fish has several possibilities of approach, including analyzes of gonadal morphology that can be made at macro, micro and ultramicroscopic level. The comprehension of cellular modifications may be important in understanding the reproductive cycle. In females, the growth and maturation of ovarian follicles rely on a carefully designed communication between follicular cells and oocyte, and a precisely organized contractile system. Changes in these systems seem to be related to apoptotic cells. This extensive remodeling of gonadal tissue due to cell proliferation and differentiation, promotes changes of the extracellular matrix. The histological and ultrastructural analyses we propose in this project were not addressed in previous studies on the reproduction of Astyanax altiparanae. Accordingly, we intend to provide additional and detailed information regarding the cell-cell and cell-matrix interactions. These data, together with the structural and ultrastructural ovarian descriptions, will enable a better understanding of reproduction of this species. Therefore, females of A. altiparanae will be collected monthly, and then macroscopic and microscopic descriptions of the ovaries will be made. The germinal cells types and their associated cells will also be described, considering aspects observed by light microscopy and transmission electron microscopy. The stages of the reproductive cycle will be established by counting the germ cell types, followed by calculation of the proportion of cell classes. The morphofunctional characterization of the gonad along the stages of the reproductive cycle, given the structures of the cytoskeleton, cell junctions and extracellular matrix, will be evaluated through immunocytochemical markers. The finding of steps of proliferation and cell death will be made using the techniques of PCNA and TUNEL, respectively. The immunocytochemical analyzes will be evaluated according to the distribution of the marking and immunostained nucleus count.
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